Whenever a medical article comes in contact with a patient, a risk of infection is created. Thus, a contaminated examination glove, tongue depressor, or stethoscope could transmit infection. The risk of infection dramatically increases for invasive medical articles, such as intravenous catheters, arterial grafts, endotracheal or intracerebral shunts and prosthetic devices, which not only are, themselves, in intimate contact with body tissues and fluids, but also create a portal of entry for pathogens.
A number of methods for reducing the risk of infection have been developed which incorporate anti-infective compounds into medical articles. Ideally, such articles provide effective levels of an anti-infective compound during the entire period that the article is being used. This sustained release may be problematic to achieve, in that a mechanism for dispersing an anti-infective compound over a prolonged period of time may be required, and the incorporation of sufficient amounts of anti-infective compound may adversely affect the surface characteristics of the article. The difficulties encountered in providing effective anti-microbial protection increase with the development of drug-resistant pathogens.
Two well known anti-infective compounds are chlorhexidine and triclosan. The following patents and patent applications relate to the use of anti-microbial compounds in medical articles.
U.S. Pat. No. 4,723,950 by Lee relates to a microbicidal tube which may be incorporated into the outlet tube of a urine drainage bag. The microbicidal tube is manufactured from polymeric materials capable of absorbing and releasing antimicrobial substances in a controllable, sustained, time-release mechanism, activated upon contact with droplets of urine, thereby preventing the retrograde migration of infectious organisms into the drainage bag. The microbicidal tube may be produced by one of three processes: (1) a porous material, such as poly-propylene, is impregnated with at least one microbicidal compound, and then coated with a hydrophilic polymer which swells upon contact with urine, causing the leaching-out of the microbicidal compound; (2) a porous material, such as high density polyethylene, is impregnated with a hydrophilic polymer and at least one microbicidal compound; and (3) a polymer, such as silicone, is compounded and co-extruded with at least one microbicidal compound, and then coated with a hydrophilic polymer. A broad range of microbicidal compounds are disclosed, including chlorhexidine and triclosan, and combinations thereof. The purpose of Lee's device is to allow the leaching out of microbicidal compounds into urine contained in the drainage bag; similar leaching of microbicidal compounds into the bloodstream of a patient may be undesirable.
U.S. Pat. No. 5,091,442 by Milner relates to tubular articles, such as condoms and catheters, which are rendered antimicrobially effective by the incorporation of a non-ionic sparingly soluble antimicrobial compound, such as triclosan. The tubular articles are made of materials which include natural rubber, polyvinyl chloride and polyurethane. Antimicrobial compound may be distributed throughout the article, or in a coating thereon. A condom prepared from natural rubber latex containing 1% by weight of triclosan, then dipped in an aqueous solution of chlorhexidine, is disclosed. U.S. Pat. Nos. 5,180,605 and 5,261,421, both by Milner, relate to similar technology applied to gloves.
U.S. Pat. Nos. 5,033,488 and 5,209,251, both by Curtis et al, relate to dental floss prepared from expanded polytetrafluoroethylene (PTFE) and coated with microcrystalline wax. Antimicrobial compounds such as chlorhexidine or triclosan may be incorporated into the coated floss.
U.S. Pat. No. 5,200,194 by Edgren et al. relates to an oral osmotic device comprising a thin semipermeable membrane wall surrounding a compartment housing a “beneficial agent” (that is at least somewhat soluble in saliva) and a fibrous support material composed of hydrophilic water-insoluble fibers. The patent lists a wide variety of “beneficial agents” which may be incorporated into the oral osmotic device, including chlorhexidine and triclosan.
International Patent Application No. PCT/GB92/01481, Publication No. WO 93/02717, relates to an adhesive product comprising residues of a co-polymerizable emulsifier comprising a medicament, which may be povidone iodine, triclosan, or chlorhexidine.
U.S. Pat. Nos. 5,019,096 and 5,616,338, both by Fox, Jr. et al. relate to infection-resistant medical articles comprising a synergistic combination of a silver compound (such as silver sulfadiazine) and chlorhexidine and their methods of manufacture, respectively. U.S. Pat. No. 5,334,588 by Fox, Jr. et al. relates to methods of inhibiting transmission of Hepatitis B virus using compositions comprising silver sulfadiazine and preferably further comprising a biguanide such as chlorhexidine and/or a detergent such as sodium deoxycholate.
U.S. Pat. Nos. 5,567,495, 5,772,640, 6,083,208 and 6,106,505 and U.S. patent publication Ser. Nos. 2001/0010016, 2001/0024661, 2002/0122876 and 2002/0173775, all by Modak et al., provide for, inter alia, anti-infective medical devices, either hydrophobic or hydrophilic, impregnated, coated, or impregnated and coated with various combinations of chlorhexidine, a silver salt such as silver sulfadiazine, silver oxide, silver carbonate or silver nitrate among others, a bismuth salt such as bismuth nitrate, bismuth citrate or bismuth salicylate among others, a zinc salt, a cerium salt, triclosan, combinations of chlorhexidine free base and chlorhexidine acetate, benzalkonium chloride, citrate, povidone iodine, parachiorometaxylene, gramicidin, polymixin, norfloxacin, tobramycin, sulfamylon, polyhexamethylene biguanide, alexidine, iodine, rifampicin, miconazole, bacitracin, and minocycline.
United States Patent Application Publication No. US 20060099237 A1 relates to combinations of octoxyglycerin and anti-infective compounds that synergistically increase the anti-infective properties of medical articles impregnated and/or coated with various combinations of octoxyglycerin and anti-infective compounds relative to the anti-infective properties of medical articles impregnated and/or coated with the same anti-infective compounds without octoxyglycerin.
Salicylic acid, an organic β-hydroxy acid, traditionally used as an antithrombogenic agent, has been recently shown to affect bacterial infection and virulence. In endocarditis, Staphylococcus aureus causes endovascular infections, damaging endothelial cells of valvular tissue. Salicylic acid appears to mitigate the virulent effects, reducing growth and cellular density of S. aureus-induced infective endocarditis in an animal model (Kupferwasser et al., 1999 “Acetylsalicylic Acid Reduces Vegetation Bacterial Density, Hematogenous Bacterial Dissemination, and Frequency of Embolic Events in Experimental Staphylococcus aureus Endocarditis Through Antiplatelet and Antibacterial Effects,” Circulation, 99:2791-2797; Kupferwasser et al., “Salicylic acid attenuates virulence in endovascular infections by targeting global regulatory pathways in Staphylococcus aureus,” J Clin Invest. 2003; 112(2):222-33). In fact, salicylic acid modulates virulence by suppressing expression of adherence factors (Kupferwasser et al., “Salicylic acid attenuates virulence in endovascular infections by targeting global regulatory pathways in Staphylococcus aureus,” J Clin Invest. 2003; 112(2):222-33).
U.S. Pat. No. 6,582,719, International Patent Application No. PCT/US02/03087, and pending U.S. patent application Ser. No. 10/633,204, filed Jul. 30, 2003, all of which are incorporated by reference, disclose antimicrobial compositions comprising antiseptics, such as chlorhexidine, triclosan, and benzalkonium chloride, and antibiotics, such as minocycline, which may be particularly useful against antibiotic-resistant microorganisms. It has been discovered, however, that although certain of the chlorhexidine-containing solutions exhibited a broad spectrum of activity against many organisms, the solutions became unstable, forming precipitates after a few days at room temperature. Having a short shelf life limits the application of these compositions in coating and impregnating medical devices.
Alkanediols are emollient solvents used in various applications, including in the cosmetics industry. Alkanediols are reported to have anti-fungal activity (Gershon, 2006, J. Pharm. Sci. 69(4):381-384).